As will be appreciated herein below, except as otherwise indicated, aluminium alloy designations and temper designations refer to the Aluminum Association designations in Aluminum Standards and Data and the Registration Records, as published by the Aluminum Association in 2009.
For any description of alloy compositions or preferred alloy compositions, all references to percentages are by weight percent unless otherwise indicated.
There are several Sc-containing aluminium alloys known in the art.
U.S. Pat. No. 5,624,632 discloses an aluminium alloy product, the composition is substantially zinc-free and lithium-free, and has 3 to 7% Mg, 0.05 to 0.2% Zr, 0.2 to 1.2% Mn, up to 0.15% Si, and 0.05 to 0.5% of a dispersoid-forming element selected from the group consisting of: Sc, Er, Y, Gd, Ho, or Hf, balance aluminium and inevitable impurities. The aluminium alloy product is said to be especially suited for applications where damage tolerance is required.
U.S. Pat. No. 6,139,653 discloses aluminium alloy consisting of 4 to 8% Mg, 0.05 to 0.6% Sc, 0.1 to 0.5% Mn, 0.05 to 2% Cu or Zn, 0.05 to 0.20% Hf or Zr, and the balance aluminium and incidental impurities. It further discloses an aluminium alloy consisting of 4 to 8% Mg, 0.05 to 0.6% Sc, 0.05-2% Cu or Zn, 0.05 to 0.20% Hf or Zr, and the balance aluminium and incidental impurities.
U.S. Pat. No. 6,531,004 discloses a weldable, corrosion-resistant aluminium alloy having 5 to 6% Mg, 0.05 to 0.15% Zr, 0.05 to 0.12% Mn, 0.01 to 0.2% Ti, 0.05 to 0.5% by total of Sc and Tb, and at least 0.1 to 0.2% Cu or 0.1 to 0.4% Zn, the balance being aluminium and unavoidable contaminants not exceeding 0.1% Si. It is reported in this document that in the sensitised condition due to the low Mn-content an improved corrosion resistance is obtained.
There is a demand for aluminium alloy articles containing Sc as purposive alloying element with an improved balance in strength and weldability.